Technical Drawings Sketch by Leonardo DaVinci. 500 years ago

Two types of technical drawings Engineering Drawing Diagram

Lines used in Technical Drawings Pg. 338-339 in textbook.

Geometric Lines Lines drawn according to the rules of geometry. ALWAYS drawn using a pencil, ruler and compass.

Three ways to produce technical drawings. 1. sketch 2. technical drawing 3. Computer assisted design

Projections A representation of a 3-D object on a 2-D surface.

Isometric Projection The lines that represent the height, length and depth form 120 degree angles on paper.

Multiview Projections

ACTIVITY Project the following object:

Oblique projection

Engineering Drawings General Arrangement: a technical drawing that represents the overall appearance of the object. ALWAYS TO SCALE, SHOW FRONT, SIDE AND TOP VIEW.

Exploded View: The various parts of the object are separated from one another.

Detailed Drawing: Specifies all the relevant information for manufacturing a part.

Dimensional Tolerances An indicator of the maximum acceptable difference between a specified measurement and the actual measurement on the finished object.

Functional Dimensioning This information on the drawing specifies the information required to do the work.

Developments A representation of the surface area required to make a part by bending. Pg 407 of text.

Diagrammatic represnetations A DIAGRAM is a simplified representation of an object, a part of an object, or a system. Design plan Technical diagram Circuit diagram

Design Plan Pg 409 in text. Name of the parts Movement of the parts Operational forces involved (constraints)

Technical Diagram Deals with the manufacturing process as opposed to the operating principles (design plan).

Circuit diagram